I am trying to interface a pair of Chinese calipers with my Arduino. Due to the calipers running at 1.5v, I've used a TPQ-2222 (quad 2N2222 transistors I think, please let me know if I'm mistaken) to step up the voltage to 5v. However, on power up, the Arduino fires voltage down it's pins randomly and I'm worried that that voltage may damage my calipers. Unfortunately I don't have any diodes on hand (they are on order from china, ETA 2 weeks...but they were cheap! And I'm not paying $3 for 10 diodes at my local electronics shop!)
Can I use the transistors on the TPQ-2222 as a signal diode and is it necessary because the transistor amplifying the voltage will already work as one?